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We propose to advance the understanding of the zoonotic risk posed by ExPEC in poultry products to fill the existing gaps in our knowledge regarding ExPEC biology and transmission; moreover, our project proposes to evaluate a safe, easy to use Salmonella-based vaccine, to protect against ExPEC infections in chickens and reduce or eliminate the risk of contamination in poultry products.Our specific research objectives are to:(i) identify the presence of different sub-pathotypes of ExPEC from healthy chicken intestine (a potential reservoir of ExPEC) and poultry meat and eggs from retail markets (potential vehicles of ExPEC to humans);(ii) ascertain if subset(s) of these ExPEC are able to cause different human ExPEC infections in animal models; and(iii) develop and evaluate a Salmonella-based vaccine expressing ExPEC antigens to protect against ExPEC infections in chickens and eradicate their presence in chicken products to eliminate their transmission through the food chain to humans.Success will provide improved human and poultry health, an economic benefit to producers and will enhance food safety.
Extraintestinal pathogenic E. coli (ExPEC) is the leading cause of sepsis infections in humans, costing the US heath care system billions of dollars each year. Deaths due to ExPEC infections exceed those caused by E. coli O157 by a factor of 500. ExPEC also infect chickens causing economic losses for the poultry industry. Chicken products are now suspected as vehicle sources of ExPEC to humans. The increase in numbers of immunocompromised populations coupled with multidrug-resistance among ExPECs has challenged the treatment of their infections. One difficulty in developing an effective vaccine against ExPEC is related to their antigenic diversity. Thus, a polyvalent vaccine is required. Studies to advance our understanding of the zoonotic risk of avian ExPECs and determining strategies for their reduction in chicken food-products are needed. Therefore, we propose to extend the understanding of the zoonotic mechanisms of ExPEC and develop a strategy to prevent their carriage in chickens and their presence in poultry products. Our objectives are to (i) identify the presence of different sub-pathotypes of ExPEC from chicken intestines and poultry meat and eggs from retail markets; (ii) ascertain that different subset(s) of these ExPEC are able to cause different human ExPEC infections in mice models; and (iii) develop and evaluate a Salmonella-based vaccine expressing ExPEC antigens to protect against ExPEC infections in chickens to eliminate their presence in chicken products and/or transmission through the food chain to humans. Success will provide improved human and poultry health, an economic benefit to producers and enhanced food safety.